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When solving a location problem using aggregated units to represent demand, it is well known that the process of aggregation introduces error. Research has focussed on individual components of error, with little work on identifying and controlling total error. We provide a focussed review of some of this literature and suggest a strategy for controlling total error. Consideration of alternative criteria for evaluating aggregation schemes shows that the method selected should be compatible with the objectives of the analyses in which it is used. Experiments are described that show that two different measures of error are related in a nonlinear way to the number of aggregate demand points (q), for any value of the number of facilities (p). We focus on the parameter q/p and show that it is critical for determining the expected severity of the error. Many practical implementations of location algorithms operate within the range of q/p where the rate of change of error with respect to q/p is highest.  相似文献   
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Is the geographic trajectory of capitalism toward spatial clusteringor dispersal? Recent theoretical work in the stream of ‘relational’economic geography includes several dynamic elements that increasethe importance of spatial clustering over time. This paper developsthe concept of ‘modular production networks’ toshow that spatial clustering and dispersal can be compatible,mutually reinforcing trends. Modular production networks encompassnodes of tacit activity linked through the exchange of codifiedinformation to create global-scale production systems. In placeslike Silicon Valley, industry participants rely on the benefitsof proximity to help build and manage global-scale productionnetworks.  相似文献   
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There is a long history of human interaction with plants of the Aroideae subfamily (Araceae). Despite these plants' chemical defenses against animal and vegetal predation, humans have targeted their starchy corms, tubers and rhizomes for dietary purposes. In the Eastern Woodlands of North America, early Europeans described the Native population as utilizing the highly acridic Peltandra virginica (arrow arum) for subsistence needs. In order to render this resource edible, however, the acridic principle first needs to be eliminated. Our study investigates the affect these processing activities have on the integrity of arrow arum starch grains. Findings from this study demonstrate that environmental variables specific to individual processing procedures may be more influential on starch grain survival than simply the temperatures reached during cooking.  相似文献   
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Book Reviews     
A Feng 阿风, Ming Qing shidai funü de diwei yu quanli: yi Ming Qing qiyue wenshu, susong dang’an wei zhongxin 明清时代妇女的地位与权利——以明清契 约文书,诉讼档案为中心 (The status and rights of women during Ming and Qing times: focused on contractual documents and litigation archives of the Ming and Qing);Eli Alberts, A History of Daoism and the Yao People of South China;Robert Ford Campany, Making Transcendents: Ascetics and Social Memory in Early Medieval China;Barbara Hendrischke, The Scripture on Great Peace: The “Taiping Jing” and the Beginnings of Daoism (Daoist Classics);Jin Jiang, Women Playing Men: Yue Opera and Social Change in Twentieth-Century Shanghai;Ma Liangkuan 马亮宽, Fu Sinian shehui zhengzhi huodong yu sixiang yanjiu 傅 斯年社会政治活动与思想研究 (A study of Fu Sinian’s thought and social-political work);Daniel J. Meissner, Chinese Capitalists versus the American Flour Industry, 1890–1910: Profit and Patriotism in International Trade;Rong Xinjiang 荣新江, Sui Tang Chang’an: xingbie, jiyi ji qita 隋唐长安: 性别, 记忆及其他 (Sui-Tang Chang’an: gender, memory, and other);Wen-hsin Yeh, Shanghai Splendor: Economic Sentiments and the Making of Modern China, 1843–1949  相似文献   
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The remains of Henry V's flagship, the Grace Dieu, currently lie buried within the inter-tidal sediments of the River Hamble (S. England). Previous archaeological investigations have been hindered by difficult excavation conditions resulting in a poor understanding of the dimensions, shape and degradation state of the hull's deeper structure. This study therefore aimed to image, characterize and reconstruct the buried remains of this vessel using a high-resolution 3D acoustic sub-bottom Chirp system with RTK-GPS positioning capability. The accurate navigation and high-resolution data that were acquired enabled the construction of a full 3D image of the site that not only identified the remains of the wooden hull, but also features buried within it. In addition, the degradation state of these buried wooden remains were investigated by calculating reflection coefficients while a hypothetical larger reconstruction of the Grace Dieu's hull was achieved, through the use of the ShipShape ship design software package.  相似文献   
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Combined application of GIS modeling of polity boundaries and qualitative characterization of those boundaries in the Tuxtla Mountains, southern Veracruz, Mexico generated interesting questions and some answers regarding the regional political landscape. Not only did this process elucidate possible boundary locations, the process of evaluating these different hypotheses proved to be a useful exercise in characterizing the boundary and the nature of interaction between the polities controlled by Matacapan and Totocapan during the Classic period. I develop a seven variable classification for political boundaries to be used with coarse-grained settlement data.  相似文献   
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